Histologic and Genotypic Characterization of Lung Cancer in the Inuit Population of the Eastern Canadian Arctic

Abstract

Inuit are the Indigenous Arctic peoples and residents of the Canadian territory of Nunavut who have the highest global rate of lung cancer. Given lung cancer’s mortality, histological and genomic characterization was undertaken to better understand the disease biology. We retrospectively studied all Inuit cases from Nunavut’s Qikiqtani (Baffin) region, referred to the Ottawa Hospital Cancer Center between 2001 and 2011. Demographics were compiled from medical records and tumor samples underwent pathologic/histologic confirmation. Tumors were analyzed by next generation sequencing (NGS) with a cancer hotspot mutation panel. Of 98 patients, the median age was 66 years and 61% were male. Tobacco use was reported in 87%, and 69% had a history of lung disease (tuberculosis or other). Histological types were: non-small cell lung carcinoma (NSCLC), 81%; small cell lung carcinoma, 16%. Squamous cell carcinoma (SCC) represented 65% of NSCLC. NGS on 55 samples demonstrated mutation rates similar to public lung cancer datasets. In SCC, the STK11 F354L mutation was observed at higher frequency than previously reported. This is the first study to characterize the histologic/genomic profiles of lung cancer in this population. A high incidence of SCC, and an elevated rate of STK11 mutations distinguishes this group from the North American population.

Lung cancer in First Nations, Inuit, and Métis peoples in Canada – a scoping review

“…Seven focused on First Nations peoples [ 22 , 25 , 27 , 28 , 30 , 31 , 33 ], while two articles were explicitly focused on Métis people in Canada [ 28 , 32 ]. Likewise, out of the extracted literature, only two articles focused on lung cancer alone [ 21 , 24 ]. The remaining twenty articles addressed or analysed cancer incidence, mortality, or patient experiences with cancer care of which lung cancer was a central aspect.…”

“…[ 21 ] conducted the first histological and genotypic characterisation of lung cancer amongst Inuit in Canada. The authors utilised medical records and tumour samples from deceased Inuit patients referred from the Eastern Arctic to TOHCC between 2001 and 2011 with a lung cancer diagnosis.…”

“… Smoking is a large contributor to lung cancer as well as changes in diet away from nutrient rich traditional foods. Galloway et al [ 20 ] Nunavut N/A In-depth interviews Inuit To understand the experiences of families and patients in Nunavut in cancer and end-of-life care Need for cultural awareness, and shared decision making in lung cancer diagnosis and treatment planning Goss et al [ 21 ] Nunavut 2001–2011 Retrospective chart review; tumor pathologic/histologic confirmation Inuit To understand lung cancer’s mortality, histological and genomic characterization in Nunavut Most cases were non-small cell lung cancer (81%) with 65% of these being squamous cell carcinoma. An elevated STK11 mutation unique to this population.…”

Nunavimmi puvakkut kaggutimik aanniaqarniq: Qanuilirqitaa?Lung cancer in Nunavik: How are we doing? A retrospective matched cohort study

“…**Ratio of Montréal:Nunavik is less than 2:1 because for 1 Nunavik resident only 1 Montréal match could be found; chart review determined 1 Nunavik resident classified as having non-small cell lung cancer in the registry actually had small cell lung cancer, and hence they were left unmatched; we excluded 1 Montréal resident labelled as having small cell lung cancer in the registry because no evidence of histologic confirmation was found during chart review. in other Inuit Nunangat populations 21 and means that disparities in survival are likely to worsen in the short term, as mutationtargeted molecular therapies that dramatically improved survival in adenocarcinoma have not been developed for squamous cell carcinoma. 22 Distinctions-based approaches should be applied when studying health outcomes of Indigenous populations.…”

Updated Views in Targeted Therapy in the Patient with Non-Small Cell Lung Cancer

“…Histologically, it is composed of bronchial glands with a tendency toward a papillary configuration that degenerate by the proliferation of type II pneumocytes, generating atypical alveolar hyperplasia, and subsequently, invasive neoplasia. The WHO 2021 classification allows differentiating lesions according to their invasive potential, i.e., minimally invasive mucinous or nonmucinous lesions and nonmucosal invasive lesions, where four subtypes can be differentiated, such as acinar, papillary, lepidic, micropapillary and solid adenocarcinomas, invasive mixed mucinous lesions and others much less frequent such as colloid, fetal, enteric adenocarcinomas, each with diagnostic peculiarities, prognosis and management [ 16 ].…”